SQL3

---

SQL3 includes the following essential features: (i) extensions of SQL2, (ii) value and object types, and (iii) subtables.

Extensions of SQL2

• Monitoring integrity constraints by using triggers.
• Improved security measures based on the Grant and Revoke commands.
• Extended query possibilities by using recursion, additional predicates, extended join operations etc. For example, Find all the amendments of the technical report with the acronym ZZ122:
  
  


• A restricted possibility to define complex structured values by means of the ROW data type, which renders an attribute tuple-value.
  
  


• New, predefined data types, in particular
  • Enumeration types: For example,
    
    
    type CLASS = [FRESH, SOPH, JUNIOR, SENIOR]
  
  
  • Boolean values.
  • Collection types: Nested tables and varying arrays.
  • Large objects (LOBs) for holding large storage objects such as
    • Binary (BLOBs),
    • Character (CLOBs), or
    • Binary files (BFILEs).